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Preparation method of benzoxaborole compound
The invention discloses a preparation method of a benzoxaborole compound. The preparation method comprises the following steps: (1) reacting raw materials containing halogenated hydrocarbon and boric acid ester under an alkaline condition, acidifying and hydrolyzing to obtain an intermediate VI; and (2) reacting a raw material containing the intermediate VI with halogenated cyanophenyl to obtain the benzoxaborole compound. The raw materials are low in price, the preparation cost of the benzoxaborole compound is reduced, the steps of protection and de-protection of organic groups are not needed in the preparation process, the reaction process is simplified, and yield reduction caused by group protection is avoided; and meanwhile, the method is mild in reaction condition, low in equipment requirement and easy for large-scale industrial production.
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Paragraph 0190-0209

(2021/07/17)

Novel arylcarbamate-N-acylhydrazones derivatives as promising BuChE inhibitors: Design, synthesis, molecular modeling and biological evaluation
A novel series of arylcarbamate-N-acylhydrazones derivatives have been designed and synthesized as potential anti-cholinesterase agents. In vitro studies revealed that these compounds demonstrated selective for butyrylcholinesterase (BuChE) with potent inhibitory activity. The compounds 10a-d, 12b and 12d were the most potent BuChE inhibitors with IC50 values of 0.07–2.07 μM, highlighting the compound 10c (IC50 = 0.07 μM) which showed inhibitory activity 50 times greater than the reference drug donepezil (IC50 = 3.54 μM). The activity data indicates that the position of the carbamate group in the aromatic ring has a greater influence on the inhibitory activity of the derivatives. The enzyme kinetics studies indicate that the compound 10c has a non-competitive inhibition against BuChE with Ki value of 0.097 mM. Molecular modeling studies corroborated the in vitro inhibitory mode of interaction and show that compound 10c is stabilized into hBuChE by strong hydrogen bond interaction with Tyr128, π-π stacking interaction with Trp82 and CH?O interactions with His438, Gly121 and Glu197. Based on these data, compound 10c was identified as low-cost promising candidate for a drug prototype for AD treatment.
Yamazaki, Diego A.S.,Rozada, Andrew M.F.,Baréa, Paula,Reis, Elaine C.,Basso, Ernani A.,Sarragiotto, Maria Helena,Seixas, Flávio A.V.,Gauze, Gisele F.
(2021/01/18)

A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft"copper(I) hydrides to previously unreactive "hard"ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.
Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
supporting information
p. 16865 - 16873
(2021/10/20)

Design and Structural Optimization of Dual FXR/PPARδActivators
Nonalcoholic steatohepatitis (NASH) is considered as severe hepatic manifestation of the metabolic syndrome and has alarming global prevalence. The ligand-activated transcription factors farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR) δhave been validated as molecular targets to counter NASH. To achieve robust therapeutic efficacy in this multifactorial pathology, combined peripheral PPAR?-mediated activity and hepatic effects of FXR activation appear as a promising multitarget approach. We have designed a minimal dual FXR/PPARδactivator scaffold by rational fusion of pharmacophores derived from selective agonists. Our dual agonist lead compound exhibited weak agonism on FXR and PPARδand was structurally refined to a potent and balanced FXR/PPARδactivator in a computer-aided fashion. The resulting dual FXR/PPARδmodulator comprises high selectivity over related nuclear receptors and activates the two target transcription factors in native cellular settings.
Schierle, Simone,Neumann, Sebastian,Heitel, Pascal,Willems, Sabine,Kaiser, Astrid,Pollinger, Julius,Merk, Daniel
supporting information
p. 8369 - 8379
(2020/08/12)

Preclinical evaluation of 1,2,4-triazole-based compounds targeting voltage-gated sodium channels (VGSCs) as promising anticonvulsant drug candidates
Epilepsy is a chronic neurological disorder affecting nearly 65–70 million people worldwide. Despite the observed advances in the development of new antiepileptic drugs (AEDs), still about 30–40% of patients cannot achieve a satisfactory seizure control. In our current research, we aimed at using the combined results of radioligand binding experiments, PAMPA-BBB assay and animal experimentations in order to design a group of compounds that exhibit broad spectrum of anticonvulsant activity. The synthesized 4-alkyl-5-substituted-1,2,4-triazole-3-thione derivatives were primarily screened in the maximal electroshock-induced seizure (MES) test in mice. Next, the most promising compounds (17, 22) were investigated in 6 Hz (32 mA) psychomotor seizure model. Protective effect of compound 22 was almost similar to that of levetiracetam. Moreover, these compounds did not induce genotoxic and hemolytic changes in human cells as well as they were characterized by low cellular toxicity. Taking into account the structural requirements for good anticonvulsant activity of 4-alkyl-5-aryl-1,2,4-triazole-3-thiones, it is visible that small electron-withdrawing substituents attached to phenyl ring have beneficial effects both on affinity towards VGSCs and protective activity in the animal models of epilepsy.
Kaproń, Barbara,?uszczki, Jarogniew J.,Siwek, Agata,Karcz, Tadeusz,Nowak, Gabriel,Zagaja, Miros?aw,Andres-Mach, Marta,Stasi?owicz, Anna,Cielecka-Piontek, Judyta,Kocki, Janusz,Plech, Tomasz
(2019/11/13)

Synthesis of novel xanthene based analogues: Their optical properties, jack bean urease inhibition and molecular modelling studies
In this work, a series of the rhodamine 6G based derivatives 5a-5g, were synthesized. The structural framework of the synthesized compounds was established by using 1H NMR, 13C NMR, FT-IR, and LC-MS analytical methods. The spectroscopic properties of the target compounds were determined by using absorption and fluorescence study in four different solvents. Furthermore, the synthesized derivatives were assessed for in-vitro screening against jack bean urease inhibition and in-silico molecular docking study. The result reveals that all the compounds exhibit good urease inhibitory activity against this enzyme but among the series, the compound 5a & 5c with an IC50 values of 0.1108 ± 0.0038 μM and 0.1136 ± 0.0295 μM shows to be most auspicious inhibitory activity compared to a standard drug (Thiourea) having IC50 value 4.7201 ± 0.0546 μM. Subsequently, the molecular docking experiment was analysed to distinguish the enzyme-inhibitor binding interaction.
Dige, Nilam C.,Hassan, Mubashir,Lee, Ki Hwan,Mahajan, Prasad G.,Raza, Hussain,Seo, Sung-Yum,Vanjare, Balasaheb D.
(2020/07/21)

New imidazo[2,1-: B] thiazole-based aryl hydrazones: Unravelling their synthesis and antiproliferative and apoptosis-inducing potential
Herein, we have designed and synthesized new imidazo[2,1-b]thiazole-based aryl hydrazones (9a-w) and evaluated their anti-proliferative potential against a panel of human cancer cell lines. Among the synthesized compounds, 9i and 9m elicited promising cytotoxicity against the breast cancer cell line MDA-MB-231 with IC50 values of 1.65 and 1.12 μM, respectively. Cell cycle analysis revealed that 9i and 9m significantly arrest MDA-MB-231 cells in the G0/G1 phase. In addition, detailed biological studies such as annexin V-FITC/propidium iodide, DCFH-DA, JC-1 and DAPI staining assays revealed that 9i and 9m triggered apoptosis in MDA-MB-213 cells. Overall, the current work demonstrated the cytotoxicity and apoptosis-inducing potential of 9i and 9m in breast cancer cells and suggested that they could be explored as promising antiproliferative leads in the future. This journal is
Babu, Bathini Nagendra,Devi, Ganthala Parimala,Kamal, Ahmed,Kumar, C. Ganesh,Rani Routhu, Sunitha,Shareef, Mohd Adil
supporting information
p. 1178 - 1184
(2020/11/03)

Design potential selective inhibitors for human leukocyte common antigen-related (PTP-LAR) with fragment replace approach
The overexpression of PTP-LAR could cause the insulin resistance, so PTP-LAR might be a promising target for treating diabetes. In this study, we applied the computer modeling methods with fragment replace approach to screen the fragment database by targeting PTP domain and site B with the aim to discover potent and selective PTP-LAR inhibitors. A series of novel 4-thiazolidone derivatives were gained. The results of their ADMET predictions indicated that these new compounds might become drug candidates. The series of these derivatives were synthesized. Subsequently, their PTP-LAR inhibitory activities were assayed. The compound7d showed highly selectivity for PTP-LAR (10.41 μM) over its close homolog PTP1B (IC50=44.40 μM), SHP2 (IC50>122.81 μM) and CDC25B (IC50>122.81 μM) and docking and molecular dynamics simulation were applied to propose the most likely binding mode of compound7d with PTP-LAR. Thus, our findings reported here may pave a way for discovering potential selective PTP-LAR inhibitors. AbbreviationsPTP-LAR Human leukocyte common antigen-relatedPTP Protein Tyrosine PhosphataseIR insulin receptorPTP1B Protein tyrosine phosphatase-1BLRP Lung resistance proteinADMET absorption, distribution, metabolism, excretion, toxicityPPB plasma protein bindingBBB blood brain barrier penetrationCYP450 cytochrome P450HIA human intestinal absorptionTLC thin-layer chromatographyUV Ultra VioletNMR nuclear magnetic resonanceTMS tetramethylsilaneMS mass spectrometryANM anisotropic network modePDB Protein Data BankDMF N,N-DimethylformamidepNPP para-nitrophenyl phosphateDTT dithiothreitolMD molecular dynamicRMSD root-mean-square deviationRMSF root-mean-square fluctuationSPC single-point chargePME Particle Mesh EwaldMM-PBSA molecular mechanics Poisson Boltzmann surface areaH bond, hydrogen bondVDW Van der Waals Communicated by Ramaswamy H. Sarma.
Li, Hong-Lian,Li, Wei-Ya,Lu, Xin-Hua,Ma, Ying,Tang, Xue,Wang, Run-Ling,Wu, Jing-Wei,Zhang, Huan,Zheng, Zhi-Hui
p. 5338 - 5348
(2019/12/24)

Synthesis of Highly Substituted Phenols and Benzenes with Complete Regiochemical Control
Substituted phenols are requisite molecules for human health, agriculture, and diverse synthetic materials. We report a chemical synthesis of phenols, including penta-substituted phenols, that accommodates programmable substitution at any position. This method uses a one-step conversion of readily available hydroxypyrone and nitroalkene starting materials to give phenols with complete regiochemical control and in high chemical yield. Additionally, the phenols can be converted into highly and even fully substituted benzenes.
Zhang, Xiaojie,Beaudry, Christopher M.
supporting information
p. 6086 - 6090
(2020/08/12)

Nickel-catalyzed removal of alkene protecting group of phenols, alcohols via chain walking process
An efficient nickel-catalyzed removal of alkene protection group under mild condition with high functional group tolerance through chain walking process has been established. Not only phenolic ethers, but also alcoholic ethers can be tolerated with the retention of stereocenter adjacent to hydroxyl group. The new reaction brings the homoallyl group into a start of new type of protecting group.
Meng, Chenkai,Niu, Haolin,Ning, Juehan,Wu, Wengang,Yi, Jun
(2020/02/04)

Green synthesis of zinc oxide particles with apple-derived compounds and their application as catalysts in the transesterification of methyl benzoates
ZnO nanoparticles (ZnONPs) were successfully synthesized using bravo-de-esmolfe apple extract in aqueous medium at room temperature. ZnO microparticles, prepared with a pure apple phytochemical, quercetin (ZnOq), or without phytochemicals (ZnO) were studied for comparative purposes. The re-use of apple waste for highly efficient catalyst production, based on green synthetic routes, can be added to the concept of a circular economy. The synthesized ZnO particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2adsorption/desorption Brunauer-Emmett-Teller (BET) theory. The XRD patterns indicated the formation of a hexagonal wurtzite phase with high purity and SEM and TEM analyses revealed the morphology of the particles. The apple extract produced spherical ZnONPs composed of round lamina-like structures, similar to the micro sized lamina-like shape of ZnOq and dissimilar to the flower-like shape of ZnO. The green synthesized ZnO nanoparticles (ZnONPs) led to a high product yield ofca. 96% within 24 h of reaction time in the transesterification reaction of different carboxylic esters.
Alegria, Elisabete C. B. A.,Alves, Marta M.,Fátima Montemor, M.,Pombeiro, Armando J. L.,Ribeiro, Ana P. C.,Saraiva, Marta S.,Soliman, Mohamed M. A.
p. 6488 - 6494
(2020/06/03)

Method of removing protective groups of olefins under catalytic action of nickel
The invention relates to a method of removing protective groups of olefins under the catalytic action of nickel. The method comprises following steps: dissolving olefin containing compounds into an organic solvent, carrying out reactions in the presence of a catalyst, organic ligands, bis(pinacolato)diboron, alkalis, alcohols, and water, wherein the catalyst contains nickel; after reactions, adding excess hydrochloric acid solution (1M) to adjust the pH to the acidic region, stirring the solution until the solution becomes clear; adding water and ethyl acetate to carry out extraction; washing the organic phase by saturated brine, drying the organic phase by anhydrous sodium sulfate, carrying out condensation, and adopting a 200-300 mesh silica gel column to carry out chromatographic separation to obtain compounds that contains alcohols or phenol. The provide method has the advantages that the adopted chemical reagents are common, the primary alkyl halide protective groups of olefins can be removed efficiently, and the method has a good application prospect in the field of organic synthesis and good industrial potential.
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(2019/10/04)

Unprecedented alkylation of carboxylic acids by boron trifluoride etherate
The alkylation of carboxylic acids by an ethyl moiety of boron trifluoride etherate in the absence of ethyl alcohol from the reaction system is unexpected and novel. Both aromatic and aliphatic carboxylic acids were clearly alkylated affording good yields in short reaction times with the exception of nicotinic acid that necessitated an overnight reaction. It was noted that while ortho-substituted hydroxyl groups of carboxylic acids investigated were not affected by alkylation, those of meta- and para-substituted carboxylic acids were partially etherified. Furthermore, the alkylation reaction was found to be compatible with a range of functional groups such as halogens, amino and nitro groups except for the alkene function of undecylenic acid that underwent polymerisation with concomitant alkylation of its carboxylic acid function.
Jumbam, Ndze D.,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
p. 387 - 392
(2018/09/06)

Enantioselective Synthesis of Oseltamivir Phosphate (Tamiflu) via the Iron-Catalyzed Stereoselective Olefin Diazidation
We herein report a gram-scale, enantioselective synthesis of Tamiflu, in which the key trans-diamino moiety has been efficiently installed via an iron-catalyzed stereoselective olefin diazidation. This significantly improved, iron-catalyzed method is uniquely effective for highly functionalized yet electronically deactivated substrates that have been previously problematic. Preliminary catalyst structure-reactivity-stereoselectivity relationship studies revealed that both the iron catalyst and the complex substrate cooperatively modulate the stereoselectivity for diazidation. Safety assessment using both differential scanning calorimetry (DSC) and the drop weight test (DWT) has also demonstrated the feasibility of carrying out this iron-catalyzed olefin diazidation for large-scale Tamiflu synthesis.
Li, Hongze,Shen, Shou-Jie,Zhu, Cheng-Liang,Xu, Hao
supporting information
p. 10619 - 10626
(2018/08/03)

Metal-Free Electrocatalytic Aerobic Hydroxylation of Arylboronic Acids
Hydroxylation of arylboronic acids to aryl alcohols was realized by a scalable electrocatalytic method. The present electrochemical hydroxylation employs low-cost methyl viologen as an organic cathodic electrocatalyst and involves O2 as a green and sustainable reactant. The electrochemical kinetic studies shown here can be a powerful tool to gain rich mechanistic and kinetic information and thus an in-depth understanding of the electrocatalytic mechanism.
Luo, Jian,Hu, Bo,Sam, Alyssa,Liu, T. Leo
supporting information
p. 361 - 364
(2018/01/28)

Continuous Flow Synthesis under High-Temperature/High-Pressure Conditions Using a Resistively Heated Flow Reactor
A cheap, easy-to-build, and effective resistively heated reactor for continuous flow synthesis at high temperature and pressure is herein presented. The reactor is rapidly heated directly using an electric current and is capable of rapidly delivering temperatures and pressures up to 400 °C and 200 bar, respectively. High-temperature and high-pressure applications of this reactor were safely performed and demonstrated by selected transformations such as esterifications, transesterifications, and direct carboxylic acid to nitrile reactions using supercritical ethanol, methanol, and acetonitrile. Reaction temperatures were between 300 and 400 °C with excellent conversions and good to excellent isolated product yields. Examples of Diels-Alder reactions were also carried out at temperatures up to 300 °C in high yield. No additives or catalysts were used in the reactions.
Adeyemi, Ahmed,Bergman, Joakim,Br?nalt, Jonas,S?vmarker, Jonas,Larhed, Mats
supporting information
p. 947 - 955
(2017/07/26)

Graphene Oxide: An Efficient Acid Catalyst for the Construction of Esters from Acids and Alcohols
Graphene oxide was found to be an efficient and reusable acid catalyst for the esterification reaction. A wide range of aliphatic and aromatic acids and alcohols were compatible with the standard conditions and afforded the corresponding products in good yields. The heterogeneous catalyst can be easily recovered and recycled in dichloro-ethane solvent with good catalytic activity.
Chen, Zhengwang,Wen, Yuelu,Fu, Yejuan,Chen, Hai,Ye, Min,Luo, Guotian
supporting information
p. 981 - 985
(2017/05/05)

Zinc Complexes with Cyanoxime: Structural, Spectroscopic, and Catalysis Studies in the Pivaloylcyanoxime-Zn System
Reaction of 2-hydroxyimino-4,4-dimethyl-3-oxo-pentanenitrile (common abbreviation HPiCO, pivaloyl-cyanoxime) with zinc sulfate in an aqueous solution results in the formation of the two new complexes: [Zn(PiCO){H(PiCO)2}(H2O)] (I) and tetranuclear Zn complex [Zn4(μ3-OH)2(PiCO)6 (H2O)4] (II). Both complexes were characterized by elemental analysis, IR- and UV-visible spectra, DSC/TGA studies, and X-ray analysis. In complex II, the PiCO- cyanoxime anion adopts three bidentate binding modes: O-monodentate, chelating (κ2), and bridging (2) coordinations. Also, the ligand represents the mixture of two diasteromers (cis-anti and cis-syn) that form five- and six-membered chelate rings with Zn atoms and cocrystallize in one unit cell at population of 0.57-0.43. There are two crystallographically different Zn-centers in the ASU, and two μ3-bridging hydroxo-groups arrange via inversion center the formation of an elegant tetranuclear complex. Each Zn atom has a molecule of coordinated water and is in the distorted octahedral environment. Because of the structural flexibility and multidentate propensity of the pivaloyl-cyanoxime, complex II may act as a structural model of naturally occurring Zn-containing enzymes. Indeed, compound I exhibits an efficient catalytic performance for transesterification reaction of various esters in ethanol under mild reaction conditions. Therefore, obtained results allow assignment of observed activity as green catalysis.
Opalade, Adedamola A.,Karmakar, Anirban,Rúbio,Pombeiro, Armando J. L.,Gerasimchuk, Nikolay
p. 13962 - 13974
(2017/11/24)

Structure-Based Design of 3-(4-Aryl-1H-1,2,3-triazol-1-yl)-Biphenyl Derivatives as P2Y14 Receptor Antagonists
UDP and UDP-glucose activate the P2Y14 receptor (P2Y14R) to modulate processes related to inflammation, diabetes, and asthma. A computational pipeline suggested alternatives to naphthalene of a previously reported P2Y14R antagonist (3, PPTN) using docking and molecular dynamics simulations on a hP2Y14R homology model based on P2Y12R structures. By reevaluating the binding of 3 to P2Y14R computationally, two alternatives, i.e., alkynyl and triazolyl derivatives, were identified. Improved synthesis of fluorescent antagonist 4 enabled affinity quantification (IC50s, nM) using flow cytometry of P2Y14R-expressing CHO cells. p-F3C-phenyl-triazole 65 (32) was more potent than a corresponding alkyne 11. Thus, additional triazolyl derivatives were prepared, as guided by docking simulations, with nonpolar aryl substituents favored. Although triazoles were less potent than 3 (6), simpler synthesis facilitated further structural optimization. Additionally, relative P2Y14R affinities agreed with predicted binding of alkynyl and triazole analogues. These triazoles, designed through a structure-based approach, can be assessed in disease models.
Junker, Anna,Balasubramanian, Ramachandran,Ciancetta, Antonella,Uliassi, Elisa,Kiselev, Evgeny,Martiriggiano, Chiara,Trujillo, Kevin,Mtchedlidze, Giorgi,Birdwell, Leah,Brown, Kyle A.,Harden, T. Kendall,Jacobson, Kenneth A.
p. 6149 - 6168
(2016/07/26)

ZnII and CdII MOFs based on an amidoisophthalic acid ligand: Synthesis, structure and catalytic application in transesterification
Solvothermal reaction of zinc(ii) and cadmium(ii) salts with 5-propionamidoisophthalic acid (H2L1) and 5-benzamidoisophthalic acid (H2L2) in the presence or absence of an auxiliary ligand gives rise to a series of 1D, 2D and 3D Zn(ii) or Cd(ii) self-assembled metal-organic frameworks as revealed by X-ray diffraction structural analyses: [Zn(μ-L1-μ-1κOO′:2κO′′)(formamide)2]n (1), [{Zn2(μ-L1-1κO:2κO′)2(4,4′-bipyridine)2(H2O)}·2(DMF)·5(H2O)]n (2), [Cd(μ-L1-μ-1κO2O′:2κO′′2O′′′)(DMF)]n (3), [{Zn(μ-L2-1κO:2κO′)(4,4′-bipyridine)(H2O)}·(H2O)]n (4) and [{Cd(μ-L2-μ-1κO2O′:2κO′′2O′′′)(formamide)(4,4′-bipyridine)}·(formamide)]n (5), which are also characterized by elemental analysis, IR spectroscopy and thermogravimetric analysis. The different architectures found in 1-5 result from the coordination modes of the carboxylate groups, which can assume nonbridging monodentate (in 1, 2 and 4), bridging bidentate (also in 1), bridging chelate (in 3 and 5) and chelate bidentate (also in 5) coordination. While 1 and 5 possess one dimensional double chain type structures, 3 has a 1D cyclic type structure and 2 and 4 have 2D or 3D wave-like structures, respectively. Topological analysis has shown that 1 and 5 have a 3-connected uninodal net with a topological type SP1-periodic net, 2 has a 2,4-connected binodal net, 3 has a 4-connected uninodal net structure and 4 has a more complex 2,2,2,4-connected tetranodal net. Frameworks 1-5 act as heterogeneous catalysts for the transesterification reaction of different carboxylate esters, with 4 showing the highest activity. These heterogeneous catalysts can be recycled without losing activity.
Karmakar, Anirban,Rúbio, Guilherme M. D. M.,Guedes da Silva, M. Fátima C.,Ribeiro, Ana P. C.,Pombeiro, Armando J. L.
p. 89007 - 89018
(2016/10/03)

Synthesis of novel triazoles and a tetrazole of escitalopram as cholinesterase inhibitors
A novel serie of escitalopram triazoles (60-88) and a tetrazole (89) have been synthesized and subjected to a study to establish the inhibitory potential of these compounds toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Some selectivity in inhibition has been observed. The 4-chlorophenyl- (75, IC50, 6.71 ± 0.25 μM) and 2-methylphenyl- (70, IC50, 9.52 ± 0.23 μM) escitalopram triazole derivatives depicted high AChE inhibition, while 2-fluorophenyl- (76, IC50 = 4.52 ± 0.17 μM) and 4-fluorophenyl- (78, IC50 = 5.31 ± 0.43 μM) have found to be excellent BChE inhibitors. It has also been observed that ortho, meta and para substituted electron donating groups increase the inhibition, while electron withdrawing groups reduce the inhibition. Docking analyses of inhibitors with AChE have depicted the binding energies for 70 and 75 as ΔGbind -6.42 and -6.93 kcal/mol, respectively, while ligands 76 and 78 have shown the binding affinity ΔGbind -9.04 and -8.51 kcal/mol, respectively, for BChE.
Mehr-Un-Nisa,Munawar, Munawar A.,Chattha, Fauzia A.,Kousar, Samina,Munir, Jawaria,Ismail, Tayaba,Ashraf, Muhammad,Khan, Misbahul A.
p. 6014 - 6024
(2015/11/11)

Structure activity relationship of brevenal hydrazide derivatives
Brevenal is a ladder frame polyether produced by the dinoflagellate Karenia brevis. This organism is also responsible for the production of the neurotoxic compounds known as brevetoxins. Ingestion or inhalation of the brevetoxins leads to adverse effects such as gastrointestinal maladies and bronchoconstriction. Brevenal shows antagonistic behavior to the brevetoxins and shows beneficial attributes when administered alone. For example, in an asthmatic sheep model, brevenal has been shown to increase tracheal mucosal velocity, an attribute which has led to its development as a potential treatment for Cystic Fibrosis. The mechanism of action of brevenal is poorly understood and the exact binding site has not been elucidated. In an attempt to further understand the mechanism of action of brevenal and potentially develop a second generation drug candidate, a series of brevenal derivatives were prepared through modification of the aldehyde moiety. These derivatives include aliphatic, aromatic and heteroaromatic hydrazide derivatives. The brevenal derivatives were tested using in vitro synaptosome binding assays to determine the ability of the compounds to displace brevetoxin and brevenal from their native receptors. A sheep inhalation model was used to determine if instillation of the brevenal derivatives resulted in bronchoconstriction. Only small modifications were tolerated, with larger moieties leading to loss of affinity for the brevenal receptor and bronchoconstriction in the sheep model.
Goodman, Allan,McCall, Jennifer R.,Jacocks, Henry M.,Thompson, Alysha,Baden, Daniel,Abraham, William M.,Bourdelais, Andrea
p. 1839 - 1858
(2014/06/09)

Reductive removal of methoxyacetyl protective group using sodium borohydride
Herein, we have developed a mild and selective reductive deprotection method for the MAc protected alcohols using sodium borohydride. The new deprotection conditions provide a complete orthogonality between O-MAc and other protecting groups such as tert-butyl ester, N-Boc, Fmoc, Cbz, O-TBDMS, N-benzyl, O-benzyl, O-acetyl, N-acetyl, N-MAc, etc. In addition to O-MAc deprotection, this method is also applicable for S-MAc deprotection.
Gadekar, Pradip K.,Hoermann, Maryann,Corbo, Faith,Sharma, Rajiv,Sarveswari,Roychowdhury, Abhijit
p. 503 - 506
(2014/01/06)

Zinc metal-organic frameworks: Efficient catalysts for the diastereoselective Henry reaction and transesterification
Three new compounds bearing different flexible side functional groups, viz. 2-acetamidoterephthalic acid (H2L1), 2-propionamidoterephthalic acid (H2L2) and 2-benzamidoterephthalic acid (H2L3), were synthesized and their coordination reactions with zinc(ii) were studied. X-ray crystallography showed the formation of novel metal organic frameworks with different dimensionalities, where the side functional groups of amidoterephthalic acid and/or auxiliary ligands were found to play significant roles. These frameworks [Zn2(L1)2(4,4′-bipyridine) 2(H2O)(DMF)]n (1), [Zn4(L2) 3(OH)2(DMF)2(H2O)2] n (2) and [Zn(L3)(H2O)2]n·n/ 2(1,4-dioxane) (3) act as heterogeneous polymeric solid catalysts not only for the diastereoselective nitroaldol (Henry) reaction of different aldehydes with nitroalkanes but also for transesterification reactions. These MOF-based heterogeneous catalysts can be recycled without losing their activity. This journal is the Partner Organisations 2014.
Karmakar, Anirban,Guedes Da Silva, M. Fatima C.,Pombeiro, Armando J. L.
p. 7795 - 7810
(2014/05/20)

ASK1 INHIBITING PYRROLOPYRIMIDINE DERIVATIVES
This invention relates to pyrrolopyrimidine derivatives of formula (I): where R1, X, p, R4, R2and R3are as defined herein, and their use as pharmaceuticals.
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(2012/06/30)

SYNTHESIS AND ANTICANCER ACTIVITY OF ARYL AND HETEROARYL-QUINOLIN DERIVATIVES
A compound of Formula I is disclosed as follows: or a pharmaceutically acceptable salt, prodrug, solvate, or metabolite thereof, wherein R is hydrogen, P(═O)(OH)2, P(═O)(O(C1-C18)alkylene(C6-C20)aryl)2, P(═O)(OH)(OM), P(═O)(OM)2, P═O(O2M), S(═O)(OH)2, S(═O)(O(C1-C18)alkylene(C6-C20)aryl)2, S(═O)(OH)(OM), S(═O)(OM)2; M is a monovalent or divalent metal ion, or alkylammonium ion; W is (C6-C20)aryl, (C6-C20)heteroaryl, (C1-C18)alkyl(C6-C20)aryl, (C1-C18)alkyl(C6-C20)heteroaryl, hydroxy(C6-C20)aryl, hydroxy(C6-C20)heteroaryl, (C1-C18)alkoxy(C6-C20)aryl, (C1-C18)alkoxy(C6-C20)heteroaryl, (C1-C18)alkylenedioxy(C6-C20)aryl, (C1-C18)alkylenedioxy(C6-C20)heteroaryl, halo(C6-C20)aryl, halo(C6-C20)heteroaryl, (C1-C18)alkylamino(C6-C20)aryl, (C1-C18)alkylamino(C6-C20)heteroaryl, (C1-C18)cycloalkylamino(C6-C20)aryl, or (C1-C18)cycloalkylamino(C6-C20)heteroaryl, and their OR8 substutes; R5 is (C1-C18alkoxy, hydrogen, hydroxyl, O—(C1-C18)alkyl(C6-C20)aryl, halo or OR8, or R5 and R6 are (C1-C18)dioxy provided that R7 is hydrogen; R6 is hydroxyl, O—(C1-C18)alkyl(C6-C20)aryl, halo or ORR, (C1-C18)alkoxy, (C1-C18)alkylamino, or (C1-C18)cycloalkylamino, or R6 and R7 are (C1-C18)dioxy provided that R5 is hydrogen; R7 is hydrogen, halo or OR8, hydroxyl, or O—(C1-C18)alkyl(C6-C20)aryl; and R8 is P(═O)(OH)2, P(═O)(O(C1-C18)alkyl(C6-C20)aryl)2, P(═O)(OH)(OM), or P(═O)(OM)2, P═O(O2M).
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Page/Page column 25

(2012/02/01)

Chemoselective esterification of phenolic acids in the presence of sodium bicarbonate in ionic liquids
Chemoselective esterification of phenolic acids with dialkyl sulphates or alkyl halides in the presence of sodium bicarbonate in 1,3-dialkylimidazolium ionic liquids is reported in excellent yields and less reaction time as compared to organic solvents. Copyright Taylor & Francis Group, LLC.
Ambika,Singh, Pradeep Pratap,Chauhan
p. 928 - 936
(2008/09/17)

Design principles to tune the optical properties of 1,3,4-oxadiazole- containing molecules
We have synthesized a series of oxadiazole compounds and ethynylene analogs. Our data reveal that the ring is both optically transparent in the visible range and fully conjugating while we have also discovered the presence of a non-radiative mechanism active in molecules containing common para-dialkoxy substituents adjacent to the oxadiazole ring(s). This structure leads to a greatly reduced quantum yield, in our example dropping from 95.0% to 48.0%. Through our thorough study we have revealed evidence that this is the result of a repulsive interaction between the oxadiazole and the adjacent alkoxy oxygen atom, which we believe prevents excited-state planarity. This quantum yield reduction is preventable through the design principles presented here. The Royal Society of Chemistry 2007.
Bolton, Onas,Kim, Jinsang
p. 1981 - 1988
(2008/02/08)

2-(Diethylamino)ethanethiol, a new reagent for the odorless deprotection of aromatic methyl ethers
A new reagent for the deprotection of aromatic methyl ethers, 2-(diethylamino)ethanethiol, is reported. This compound, commercially available as its HCl salt, affords the corresponding phenols in good to excellent yields on a wide variety of substrates. A clear advantage of this method over the use of more common thiols, such as ethanethiol, is the easy extraction of both the deprotecting reagent and the byproduct 2-(diethylamino)ethyl methyl sulfide into the aqueous phase by quenching with dilute acid, which allows an essentially odorless workup.
Magano, Javier,Chen, Michael H.,Clark, Jerry D.,Nussbaumer, Thomas
p. 7103 - 7105
(2007/10/03)

Antagonist analogue of 6-[3′-(1-adamantyl)-4′-hydroxyphenyl]-2- naphthalenecarboxylic acid (AHPN) family of apoptosis inducers that effectively blocks AHPN-induced apoptosis but not cell-cycle arrest
The retinoid 6-[3′-(1-adamantyl)-4′-hydroxyphenyl]-2- naphthalenecarboxylic acid (AHPN) and its active analogues induce cell-cycle arrest and programmed cell death (apoptosis) in cancer cells independently of retinoic acid receptor (RAR) interaction. Its analogue, (E)-4-[3′-(1- adamantyl)-4′-hydroxyphenyl]-3-(3′-acetamidopropyloxy)cinnamic acid (3-A-AHPC) selectively antagonized cell apoptotic events (TR3/nur77/NGFI-B expression and nuclear-to-mitochondrial translocation) but not the proliferative events (cell-cycle arrest and p21WAF1/CIP1 expression) induced by proapoptotic AHPN and its analogues. The syntheses of 3-A-AHPC and proapoptotic (E)-6-[3′-(1-adamantyl)-4′-hydroxyphenyl]-5- chloronaphthalenecarboxylic acid (5-Cl-AHPN) are described. Computational studies on AHPN, AHPC, and three substituted analogues (5-Cl-AHPN, 3-Cl-AHPC, and 3-A-AHPC) suggested reasons for their diametric effects on RAR activation. Density functional theory studies indicated that the 1-adamantyl (1-Ad) groups of the AHPN and AHPC configurations assumed positions that were nearly planar with the aromatic rings of their polar termini. In contrast, in the configurations of the substituted analogues having chloro and 3-acetamidopropyloxy groups, rather than a hydrogen, ortho to the diaryl bonds, the diaryl bond torsion angles increased so that the 1-Ad groups were oriented out of this plane. Docking and molecular dynamics of AHPN, AHPC, and these substituted analogues in the RARγ ligand-binding domain illustrated how specific substituents on the AHPN and AHPC scaffolds modulated the positions and dynamics of the 1-Ad groups. As a result, the position of RARγ helix H12 in forming the coactivator-binding site was impacted in a manner consistent with the experimental effect of each analogue on RARγ transcriptional activation.
Dawson, Marcia I.,Harris, Danni L.,Liu, Gang,Hobbs, Peter D.,Lange, Christopher W.,Jong, Ling,Bruey-Sedano, Nathalie,James, Sharon Y.,Zhang, Xiao-Kun,Peterson, Valerie J.,Leid, Mark,Farhana, Lulu,Rishi, Arun K.,Fontana, Joseph A.
p. 3518 - 3536
(2007/10/03)

Asymmetric synthesis of the putative structure of (-)-oryzoxymycin.
[reaction: see text] A short asymmetric synthesis of (2'S,5R,6R)-2'-[6-amino-5-hydroxy-1,3-cyclohexadiene-1-carbonyloxy]propionic acid, the enantiomer of the reported structure of (+)-oryzoxymycin is described. The reported spectral data does not match that obtained for synthetic "oryzoxymycin".
Bunnage, Mark E,Ganesh, Thota,Masesane, Ishmael B,Orton, Darren,Steel, Patrick G
p. 239 - 242
(2007/10/03)

Selective deprotection of either alkyl or aryl silyl ethers from aryl, alkyl bis-silyl ethers
A pair of complementary methods was developed using CeCl3·7H2O/CH3CN and LiOH/DMF to selectively deprotect alkyl and aryl silyl ethers, respectively, from the corresponding bis-silyl ethers in excellent yields.
Ankala, Sudha V.,Fenteany, Gabriel
p. 4729 - 4732
(2007/10/03)

Use of the Wadsworth-Emmons reaction for preparing hindered vinyl ethers and related 1,2-dioxetanes
Arylaldehyde acctals can be reacted with trimethyl phosphite to produce the corresponding dimethyl α-methoxy-benzylphosphonates, themselves used in a Wadsworth-Emmons reaction with adamantanone to produce hindered methyl vinyl ethers. These vinyl ethers are useful in the preparation of chemiluminescent 1,2-dioxetanes. The scope of the reaction has been explored.
Roeschlaub, Carl A.,Sammes, Peter G.
p. 2243 - 2248
(2007/10/03)

Selective deprotection of silyl-protected phenols using solid NaOH and a phase transfer catalyst
Aryl silyl ethers can be deprotected to yield phenols in good to excellent yields using a biphasic system of 10 equivalents of NaOH and catalytic Bu4NHSO4 in 1,4-dioxane. Alkyl silyl ethers prepared using a variety of silyl protecting groups survive under these conditions, allowing selective deprotection of silyl-protected phenols in the presence of silyl- protected alcohols.
Crouch, R. David,Stieff, Mike,Frie, Jessica L.,Cadwallader, Amy B.,Bevis, Daniel C.
p. 3133 - 3136
(2007/10/03)

An efficient general method for esterification of aromatic carboxylic acids
Treatment of a variety of aromatic carboxylic acids with alcohols in the presence of thionyl chloride results in excellent yields of corresponding esters. This esterification system is compatible with a wide assortment of functional groups.
Hosangadi, Bhaskar D.,Dave, Rajesh H.
p. 6375 - 6378
(2007/10/03)

Chemistry of Fruit Flies: Composition of the Male Rectal Gland Secretions of some Species of South-East Asian Dacinae. Re-examination of Dacus Cucurbitae (Melon Fly)
The major components of the rectal glandular secretions of male Dacus (Bactrocera) umbrosus (jack fruit fly), D. (Bactrocera) nigrotibialis, D. (Bactrocera) albistrigatus, D. (Zeugodacus) tau and D. (Zeugodacus) sp. (taxonomically similar to D. tau) have been identified.Alcohols, spiroacetals, and amides are the dominant components.The major component in the rectal gland secretion of Dacus (Zeugodacus) cucurbitae (melon fly) is shown to be ethyl 4-hydroxybenzoate and not 2-ethoxybenzoic acid.
Perkins, Michael V.,Kitching, William,Drew, Richard A. I.,Moore, Christopher J.,Koenig, Wilfried A.
p. 1111 - 1117
(2007/10/02)